A liquid in which the active ingredient is completely dissolved is referred to as?

The correct term for a liquid in which the active ingredient is completely dissolved is a solution. In a solution, the solute (in this case, the active ingredient) is uniformly distributed within the solvent, leading to a clear and homogeneous mixture. This means that the entirety of the active compound is at the molecular or ionic level mixed into the solvent, allowing for easy absorption and efficacy when administered.

In contrast, other choices do not accurately describe a scenario in which an active ingredient is fully contained within a liquid. A suspension, for example, consists of solid particles dispersed in a liquid but not dissolved, resulting in a heterogeneous mixture that may require shaking or agitation before use. An emulsion involves mixing two immiscible liquids, typically oil and water, stabilized by an emulsifier; this also does not imply that the active ingredient is dissolved. Finally, a tablet refers to a solid dosage form that contains the active ingredient compressed into a specific shape and is not in liquid form. Thus, the distinction is critical for understanding the different forms of pharmaceutical preparations and their applications.